typedef	struct FController FController;typedef	struct FDrive FDrive;typedef struct FType FType; static void floppyintr(Ureg*);static int floppyon(FDrive*);static void floppyoff(FDrive*);static void floppysetdef(FDrive*); /* *  a floppy drive */struct FDrive{	FType	*t;		/* floppy type */	int	dt;		/* drive type */	int	dev; 	ulong	lasttouched;	/* time last touched */	int	cyl;		/* current arm position */	int	confused;	/* needs to be recalibrated */	int	vers;	int	maxtries;	/* max read attempts before Eio */ 	int	tcyl;		/* target cylinder */	int	thead;		/* target head */	int	tsec;		/* target sector */	long	len;		/* size of xfer */ 	uchar	*cache;		/* track cache */	int	ccyl;	int	chead;}; /* *  controller for 4 floppys */struct FController{	QLock;			/* exclusive access to the contoller */ 	int	ndrive;	FDrive	*d;		/* the floppy drives */	FDrive	*selected;	int	rate;		/* current rate selected */	uchar	cmd[14];	/* command */	int	ncmd;		/* # command bytes */	uchar	stat[14];	/* command status */	int	nstat;		/* # status bytes */	int	confused;	/* controler needs to be reset */	Rendez	r;		/* wait here for command termination */	int	motor;		/* bit mask of spinning disks */}; /* *  floppy types (all MFM encoding) */struct FType{	char	*name;	int	dt;		/* compatible drive type */	int	bytes;		/* bytes/sector */	int	sectors;	/* sectors/track */	int	heads;		/* number of heads */	int	steps;		/* steps per cylinder */	int	tracks;		/* tracks/disk */	int	gpl;		/* intersector gap length for read/write */		int	fgpl;		/* intersector gap length for format */	int	rate;		/* rate code */ 	/*	 *  these depend on previous entries and are set filled in	 *  by floppyinit	 */	int	bcode;		/* coded version of bytes for the controller */	long	cap;		/* drive capacity in bytes */	long	tsize;		/* track size in bytes */};/* bits in the registers */enum{	/* status registers a & b */	Psra=		0x3f0,	Psrb=		0x3f1, 	/* digital output register */	Pdor=		0x3f2,	Fintena=	0x8,	/* enable floppy interrupt */	Fena=		0x4,	/* 0 == reset controller */ 	/* main status register */	Pmsr=		0x3f4,	Fready=		0x80,	/* ready to be touched */	Ffrom=		0x40,	/* data from controller */	Ffloppybusy=	0x10,	/* operation not over */ 	/* data register */	Pfdata=		0x3f5,	Frecal=		0x07,	/* recalibrate cmd */	Fseek=		0x0f,	/* seek cmd */	Fsense=		0x08,	/* sense cmd */	Fread=		0x66,	/* read cmd */	Freadid=	0x4a,	/* read track id */	Fspec=		0x03,	/* set hold times */	Fwrite=		0x45,	/* write cmd */	Fformat=	0x4d,	/* format cmd */	Fmulti=		0x80,	/* or'd with Fread or Fwrite for multi-head */	Fdumpreg=	0x0e,	/* dump internal registers */ 	/* digital input register */	Pdir=		0x3F7,	/* disk changed port (read only) */	Pdsr=		0x3F7,	/* data rate select port (write only) */	Fchange=	0x80,	/* disk has changed */ 	/* status 0 byte */	Drivemask=	3<<0,	Seekend=	1<<5,	Codemask=	(3<<6)|(3<<3),	Cmdexec=	1<<6, 	/* status 1 byte */	Overrun=	0x10,};  static voidpcfloppyintr(Ureg *ur, void *a){	USED(a); 	floppyintr(ur);} voidfloppysetup0(FController *fl){	fl->ndrive = 0;	if(ioalloc(Psra, 6, 0, "floppy") < 0)		return;	if(ioalloc(Pdir, 1, 0, "floppy") < 0){		iofree(Psra);		return;	}	fl->ndrive = 2;} voidfloppysetup1(FController *fl){	uchar equip; 	/*	 *  read nvram for types of floppies 0 & 1	 */	equip = nvramread(0x10);	if(fl->ndrive > 0){		fl->d[0].dt = (equip >> 4) & 0xf;		floppysetdef(&fl->d[0]);	}	if(fl->ndrive > 1){		fl->d[1].dt = equip & 0xf;		floppysetdef(&fl->d[1]);	}	intrenable(IrqFLOPPY, pcfloppyintr, fl, BUSUNKNOWN, "floppy");} /* *  eject disk ( unknown on safari ) */voidfloppyeject(FDrive *dp){	floppyon(dp);	dp->vers++;	floppyoff(dp);} int floppyexec(char *a, long b, int c){	USED(a, b, c);	return b;}